JP2003266708A - Manufacturing method for ink-jet head - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for an ink-jet head having a high cross-linking density of an adhesive so as to improve the ink resistant performance, capable of bonding members having different coefficients of thermal expansion without warpage derived from the coefficient of thermal expansion difference. <P>SOLUTION: In the manufacturing method for an ink-jet head comprising the step of bonding with an adhesive a channel substrate 1 and a nozzle plate 2, and/or the channel substrate 1 and a cover base material 3, the adhesive is a thermosetting adhesive, and the temperature rise rate at the time of hardening of the thermosetting adhesive is in a range of 0.01-1.0°C/minute from the bonding temperature to the hardening temperature. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ink jet, and more specifically, it is possible to improve ink resistance performance by high density of an adhesive and to expand thermal expansion when joining members having different thermal expansion coefficients. The present invention relates to a method for manufacturing an ink jet that can be joined without warpage or displacement due to a difference.

[0002]

2. Description of the Related Art In manufacturing an ink jet head, it is necessary to bond a channel substrate and a nozzle plate and / or a channel substrate and a cover base material with an adhesive.

Conventionally, a room temperature curing adhesive has been used for joining different kinds of members. However, such room temperature adhesives have drawbacks such as a long curing time and poor ink resistance.

On the other hand, the thermosetting adhesive has a short curing time,
Since the ink resistance is excellent, the above problem can be solved, but the ink resistance changes depending on how the heat is applied, and there is a problem that warpage occurs due to the difference in the coefficient of thermal expansion when joining different members having different coefficients of thermal expansion. .

[0005]

SUMMARY OF THE INVENTION Therefore, according to the present invention, when a member having a high cross-linking density of an adhesive and an improved ink resistance performance is joined and a member having a different thermal expansion coefficient is joined, a warp due to a difference in thermal expansion is caused. An object of the present invention is to provide a method for manufacturing an ink jet that can be joined without any damage.

[0006]

The above-mentioned problems can be solved by the following inventions.

(Claim 1) In a method for manufacturing an ink jet head, in which a channel substrate and a nozzle plate, and / or a channel substrate and a cover substrate are joined with an adhesive, the adhesive is a thermosetting adhesive, and the thermosetting adhesive is used. The rate of temperature rise during curing of the adhesive adhesive is 0.0 from the temperature during bonding to the curing temperature.
A method of manufacturing an inkjet head, wherein the range is 1 to 1.0 ° C./min.

(2) The method of manufacturing an ink jet head according to claim 1, wherein the coefficient of thermal expansion of the channel substrate and the coefficient of thermal expansion of the nozzle plate are different.

(Claim 3) A method for manufacturing an ink jet head according to claim 1, wherein the coefficient of thermal expansion of the channel substrate and the coefficient of thermal expansion of the cover substrate are different.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a partially cutaway perspective view showing an outline of an ink jet head, and FIG. 2 is a vertical sectional view of the same head. In FIG. 1, 1 is a channel substrate, 2 is a nozzle plate, 3 is a cover substrate, 4 is a back plate, and 5 is an ink manifold.

In the present invention, the ink jet head is manufactured by bonding the channel substrate 1 and the nozzle plate 2 and the channel substrate 1 and the cover base material 3 with an adhesive.

In the present invention, a thermosetting adhesive is used as the adhesive for the joining. Examples of the thermosetting adhesive include epoxy-based, urea-based, melamine-based, phenol-based, resorcinol-based, polyester-based, polyurethane-based, and polyimide-based thermosetting adhesives.

The temperature rising rate during curing of the thermosetting adhesive in the present invention is 0.01 from the temperature at the time of adhesion to the curing temperature.
Is in the range of 1.0 ° C./min. Temperature rising rate is 0.01 ° C /
If it is less than 10 minutes, the force for absorbing the elongation at the time of joining different kinds of members is inferior, and if it exceeds 1.0 ° C./minute, there is a practical problem in applying an adhesive agent. In the present invention, the preferable temperature rising rate is in the range of 0.01 to 0.3 ° C./minute.

In the present invention, since the rate of temperature rise is regulated to be in the range of 0.01 to 1.0 ° C./minute from the bonding temperature to the curing temperature, it is possible to cure gradually.
This has the effect of increasing the crosslinking reaction and increasing the crosslinking density (ink resistance). That is, when the thermosetting adhesive is heated,
A three-dimensional crosslinking reaction (crosslinking) occurs. There is a correlation between the density of this crosslinking reaction and the ink resistance, and as the density increases, the ink resistance increases. Ink resistance is evaluated by immersing the cured adhesive layer in ink and evaluating the degree of swelling, and it is evaluated that the ink resistance is better when it does not swell. Increasing the crosslink density, that is, the ink resistance, has the effect of making it difficult for the ink to penetrate into the adhesive.

A preferred embodiment of the present invention is a channel substrate 1.
Is different from the thermal expansion coefficient of the nozzle plate 2, and the thermal expansion coefficient of the channel substrate 1 is different from the thermal expansion coefficient of the cover substrate 3. According to this aspect, when joining different types of members having different thermal expansion coefficients,
By hardening the adhesive layer little by little, the viscoelasticity of the adhesive layer is gradually increased, and in a region where the adhesive viscoelasticity exceeds the member elastic modulus, it is possible to suppress the extension of the member and solve the problem of warpage.

The ink jet head of the present invention and the method for manufacturing the same will be described in more detail below.

As the piezoelectric material used for the channel substrate 1 which is the first base material, a known piezoelectric material which is deformed by applying an electric field can be used. The substrate is made of an organic material or a non-metal substrate. Etc. In particular, a non-metal channel substrate is preferable, and examples thereof include a piezoelectric ceramics substrate formed through steps such as molding and firing, and a substrate formed without requiring molding and firing. Examples of the organic material used for the substrate made of an organic material include an organic polymer such as polyvinylidene fluoride and a hybrid material of an organic polymer and an inorganic material.

In a non-metal channel substrate, molding,
Lead zirconate titanate (PZT) is preferable as the piezoelectric ceramic substrate formed through steps such as firing.
Furthermore, BaTiO ₃ , ZnO, LiNbO ₃ , LiTaO
₃ etc. may be used. As PZT, PZT (PbZ
rO ₃ -PbTiO ₃ ) and PZT containing the third component.
Pb (Mg _1/2 Nb _2/3 ) as the third component to be added
_{O 3, Pb (Mn 1/3 Sb} 2/3) O 3, Pb (Co 1/3 Nb
There is a _2/3) O ₃ and the like. Further, the non-metal channel substrate can be formed by a sol-gel method, a laminated substrate coating method or the like as a substrate formed without requiring molding and firing.

The channel substrate 1 is composed of two channel substrates 1.
a and 1b are joined vertically with their polarization directions opposite to each other. As a means for joining the two channel substrates 1a and 1b, an epoxy adhesive or the like is used for joining. The thickness (dry film thickness) of the adhesive layer after curing is preferably in the range of 1 to 100 μm.

In the channel substrate 1, a plurality of rows of grooves parallel to each other are machined at a predetermined pitch using a known grinder such as a disk-shaped grindstone (dicing blade) to form an ink flow path for storing ink. A channel portion 10 including an ink channel 11 and an air channel 12 that does not store ink is formed, and a partition wall 13 is formed between the respective channel portions 10.

The width of the ink channel 11 is 20 to 1
The wall thickness of the partition wall 13 is 20 to 10 μm.
It is 0 μm, which is a very fine shape. Further, the thickness of the nozzle plate 2 is in the range of 20 to 100 μm, and the diameter of the nozzle hole is in the range of 10 to 40 μm, which is also a very fine shape.

After processing the channel groove, the metal electrode 6 is formed on the wall surface of each partition wall 13. As a method of forming the metal electrode 6, known methods such as a vapor deposition method, a sputtering method, and a plating method can be used. Since the partition wall 13 is composed of two channel substrates 1a and 1b having different polarization directions, each metal electrode 6
Are the channel substrates 1a and 1 which form at least the respective partition walls 13 so as to drive both the substrates 1a and 1b.
It is formed on the entire side surface extending over b.

As the metal capable of forming the metal electrode 6, there are those containing Au, Pt, Ag, Ni, Co, Cu, Al, etc. as the main components, but those containing Ni or Cu as the main components are preferable. It is particularly preferable that Ni is the main component. Especially when the metal electrode 6 is formed by a plating method, electroless plating is preferable. With electroless plating, a more uniform and pinhole-free metal film can be easily formed.

In forming electrodes by electroless plating,
Ni-P plating or Ni-B plating may be used alone, or Ni-P and Ni-B may be laminated. Since the electric resistance of Ni-P plating increases as the P content increases, the P content is preferably about 1 to several percent. Since the B content of Ni-B plating is usually less than 1%, Ni is better than Ni-P.
Ni-B is preferable to Ni-P because of its high content, low electric resistance, and good connectivity with external wiring.
Since Ni-B is expensive, it is also preferable to combine Ni-P and Ni-B. The metal electrode 6 formed of the Ni-P or Ni-B by the electroless plating method has uniform deposition and, as a result, has a smooth surface property. The thickness of the plated film is preferably in the range of 0.5 to 5 μm.

The metal electrode 6 is formed on the partition wall 13 by, for example, N.
It is also possible to form a plating film by electroless plating of i-B and then perform electroless plating treatment of Ni-P. In this case, it is also possible to make each plating metal different.
In addition, after forming a plating film on the partition wall 13 by electroless plating, electrolytic plating treatment such as gold plating may be performed on the plating film. Further, the metal electrode 6 may be formed by forming a metal film on the partition wall 13 by a sputtering method, a vapor deposition method or the like, and then performing an electrolytic plating treatment on the metal film to form a plating film.

Next, the cover substrate 3 is attached to the upper surface of the channel substrate 1 formed as described above. A non-piezoelectric substrate can be used as the cover substrate 3. As the non-piezoelectric substrate, for example, a ceramic substrate formed through steps such as molding and firing, or molding,
There are substrates and the like that are formed without the need of firing, and examples of ceramic substrates that are formed through steps such as firing include Al ₂ O ₃ , SiO ₂ , mixtures thereof, mixed melts, ZrO ₂ , BeO, AlN, SiC, etc. can be used. Alternatively, the substrate may be made of an organic material,
An organic polymer or a hybrid material of an organic polymer and an inorganic material may be used.

After the cover substrate 3 is bonded to the upper surface of the channel substrate 1 in this way, an insulating protective film for protecting the metal electrode 6 is formed in at least the ink channel 11 of the channel portion 10. Is preferred. As the insulating protective film, it is possible to apply an insulating protective film using various known materials, but it is particularly preferable to use a parylene film. In this embodiment as well, the parylene film 7 is used as the insulating protective film. When the parylene film 7 is formed, a water-based ink can be used as the ink. As a method for forming the parylene film 7, a CVD method (Chemic) using a solid diparaxylylene dimer as a vapor deposition source is used.
A known method such as al vapor deposition (gas phase synthesis method) can be used. That is, the diradical paraxylylene generated by vaporization and thermal decomposition of the diparaxylylene dimer is adsorbed on the substrate and polymerized to form a film.

If the thickness of the parylene film 7 is thinner than 1.0 μm, it becomes difficult to maintain sufficient insulation. Further, as the film thickness increases, the rigidity of the film itself restricts the movement of the partition wall 13. Therefore, it is desirable that the film thickness of the parylene film 7 is 1.0 to 10 μm, but especially 1.0 When it is in the range of up to 5.0 μm, the parylene film 7
Is formed in the ink channel 11 as a sufficiently thin film, so that sufficient ink ejection sensitivity and ink ejection characteristics can be obtained without reducing the effective area of the ink channel 11. A more preferable range of film thickness is
It is 1.0 to 3.0 μm.

When air bubbles are mixed in the ink stored in the ink channel 11 in which the parylene film 7 is formed, the air bubbles adhere to the parylene film 7, stick to the parylene film, and are difficult to escape.
Therefore, the surface of the parylene film 7 is treated with oxygen plasma,
It is preferably hydrophilized.

Next, the nozzle plate 2 having the nozzle holes 21 for ejecting ink is bonded to the front end surface of the channel substrate 1 by using an adhesive.

On the rear end surface of the channel substrate 1, an ink manifold 5 for supplying ink into the ink channel 11 via a back plate 4 having an ink introducing hole 41 is formed by using an adhesive such as an epoxy adhesive. And joined together to form an inkjet head.

[0033]

EXAMPLES The present invention will be described in detail below based on examples.

Example 1 The ink resistance of the following adhesives was evaluated as follows.

A fixed amount of the adhesive is applied to a glass plate, and after curing under the following curing conditions, various solvents (ethyl lactate, ethyl acetate, 4H4M2P,
Isoboron, BEA, NPA, cyclohexanone, DM
It was immersed in A) for 24 hours, the weights before and after the immersion were measured, the expansion coefficient due to the solvent was calculated by the following formula, and the ink resistance was evaluated. The results are shown in Table 1.

(Adhesive) Epoxy adhesive Bisphenol A diglycidyl ether (DGEBA) Dicyandiamide (DICY) Epoxy adduct curing accelerator

(Level of curing conditions) A: 0.05 ° C./min heating pattern from room temperature to 100 ° C., 1 hr at 100 ° C. B: 1.0 ° C./min heating pattern from room temperature to 100 ° C. , 100 ° C for 1 hr C: 100 ° C for 2 hr

(Evaluation Method of Ink Resistance) Expansion coefficient (%) = 100 × (after immersion-before immersion) / Before immersion The closer the expansion coefficient is to 0%, the more excellent the ink resistance can be evaluated.

[0039]

[Table 1]

4H4M2P: 4-hydroxy-4-methyl-2-pentanone BEA: 2-n-butoxyethyl acetate NPA: n-propyl acetate DMA: diethylene glycol monoethyl ether acetate

From Table 1 above, in the case of the curing condition levels A and B in which the temperature rising rate is within the range of the present invention, the expansion rate is low, the ink resistance is excellent, and the curing condition level is not regulated.
It can be seen that in C, the expansion rate is high and the ink resistance is poor.

Example 2 An ink jet head was manufactured by joining a channel substrate having a different coefficient of thermal expansion and a nozzle plate using the adhesive used in Example 1.

(Coefficient of Thermal Expansion) Coefficient of thermal expansion of the channel substrate: 7.0 × 10 ⁻⁶ cm / cm
・ ℃ Thermal expansion coefficient of nozzle plate: 2.0 × 10 ^-5 cm / c
m ・ ℃

(Evaluation of Elongation) Curing condition A of Example 1,
The nozzle plate lengths in B and C were measured before and after curing, and the elongation was calculated by the following formula, and the results are shown in Table 2. Elongation = (nozzle plate length after curing)-(nozzle plate length before curing)

[0045]

[Table 2]

[0046]

According to the present invention, the cross-linking density of the adhesive is high, the ink resistance can be improved, and when members having different thermal expansion coefficients are joined, they can be joined without warpage due to the difference in thermal expansion. An inkjet manufacturing method can be provided.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view of an inkjet head.

FIG. 2 is a partial sectional view of an inkjet head.

[Explanation of symbols]

1: Channel substrate 2: Nozzle plate 3: Cover substrate 4: Back plate 5: Ink manifold 6: Metal electrode 7: Parylene film 10: Channel part 11: Ink channel 12: Air channel 13: Partition wall

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hiroyuki Nomori             Konica Stock, 1 Sakura-cho, Hino City, Tokyo             In the company F-term (reference) 2C057 AF93 AG45 AP13 AP25

Claims (3)

[Claims] 1. A method for manufacturing an inkjet head, which comprises a step of joining a channel substrate and a nozzle plate, and / or a channel substrate and a cover base material with an adhesive, wherein the adhesive is a thermosetting adhesive. The method for manufacturing an inkjet head, wherein the temperature rising rate of the conductive adhesive during curing is in the range of 0.01 to 1.0 ° C./minute from the temperature during bonding to the curing temperature. 2. The method of manufacturing an ink jet head according to claim 1, wherein the coefficient of thermal expansion of the channel substrate and the coefficient of thermal expansion of the nozzle plate are different. 3. The method of manufacturing an ink jet head according to claim 1, wherein the coefficient of thermal expansion of the channel substrate and the coefficient of thermal expansion of the cover substrate are different.